Preoperative Serum Albumin Level as a Predictor of Operative Mortality and Morbidity: Results From the National VA Surgical Risk Study

Abstract

OBJECTIVE: To improve the precision and reliability of estimates of the association between preoperative serum albumin concentration and surgical outcomes. DESIGN: Prospective observational study. Patients were followed up for 30 days postoperatively. Multiple logistic regression models were developed to evaluate serum albumin level as a predictor of operative mortality and morbidity in relation to 61 other preoperative patient risk variables. SETTING: Forty-four tertiary care Veterans Affairs (VA) medical centers. PATIENTS: A total of 54215 major noncardiac surgery cases from the National VA Surgical Risk Study. MAIN OUTCOME MEASURES: Thirty-day operative mortality and morbidity. RESULTS: A decrease in serum albumin from concentrations greater than 46 g/L to less than 21 g/L was associated with an exponential increase in mortality rates from less than 1% to 29% and in morbidity rates from 10% to 65%. In the regression models, albumin level was the strongest predictor of mortality and morbidity for surgery as a whole and within several subspecialties selected for further analysis. Albumin level was a better predictor of some types of morbidity, particularly sepsis and major infections, than other types. CONCLUSIONS: Serum albumin concentration is a better predictor of surgical outcomes than many other preoperative patient characteristics. It is a relatively low-cost test that should be used more frequently as a prognostic tool to detect malnutrition and risk of adverse surgical outcomes, particularly in populations in whom comorbid conditions are relatively frequent.